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Bone MS, Legrand TPRA, Harvey ML, Wos-Oxley ML, Oxley APA. Aquatic conditions & bacterial communities as drivers of the decomposition of submerged remains. Forensic Sci Int 2024; 361:112072. [PMID: 38838610 DOI: 10.1016/j.forsciint.2024.112072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/24/2024] [Accepted: 05/26/2024] [Indexed: 06/07/2024]
Abstract
Aquatic decomposition, as a forensic discipline, has been largely under-investigated as a consequence of the highly complex and influential variability of the water environment. The limitation to the adaptability of scenario specific results justifies the necessity for experimental research to increase our understanding of the aquatic environment and the development of post-mortem submersion interval (PMSI) methods of estimation. This preliminary research aims to address this contextual gap by assessing the variation in the bacterial composition of aquatic biofilms as explained by water parameter measurements over time, associated with clothed and bare decomposing remains. As part of three field investigations, a total of 9 still-born piglets (n = 3, per trial) were used as human analogues and were submerged bare or clothed in either natural cotton or synthetic nylon. Changes in the bacterial community composition of the water surrounding the submerged remains were assessed at 4 discrete time points post submersion (7, 14, 21 and 28 days) by 16 S rRNA gene Next Generation Sequencing analysis and compared to coinciding water parameter measurements (i.e. conductivity, total dissolved solids (TDS), salinity, pH, and dissolved oxygen (DO)). Bacterial diversity was found to change over time and relative to clothing type, where significant variation was observed between synthetic nylon samples and bare/cotton samples. Seasonality was a major driver of bacterial diversity, where substantial variation was found between samples collected in early winter to those collected in mid - late winter. Water parameter measures of pH, salinity and DO were identified to best explain the global bacterial community composition and their corresponding dynamic trajectory patterns overtime. Further investigation into bacterial community dynamics in accordance with varying environmental conditions could potentially lead to the determination of influential extrinsic factors that may drive bacterial activity in aquatic decomposition. Together with the identification of potential bacterial markers that complement the different stages of decomposition, this may provide a future approach to PMSI estimations.
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Affiliation(s)
- Madison S Bone
- School of Life and Environmental Sciences, Deakin University, Geelong, VIC 3216, Australia.
| | | | - Michelle L Harvey
- School of Life and Environmental Sciences, Deakin University, Geelong, VIC 3216, Australia
| | | | - Andrew P A Oxley
- School of Life and Environmental Sciences, Deakin University, Geelong, VIC 3216, Australia
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Peruch M, Buffon M, Jakovski Z, Spiliopoulou C, Addobbati R, Franzin M, Magni PA, D’Errico S. Comparative Toxicological Analyses of Traditional Matrices and Blow Fly Larvae in Four Cases of Highly Decomposed Human Cadavers. INSECTS 2024; 15:500. [PMID: 39057233 PMCID: PMC11277152 DOI: 10.3390/insects15070500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 06/28/2024] [Accepted: 07/03/2024] [Indexed: 07/28/2024]
Abstract
In forensic investigation, determining the time and cause of death becomes challenging, especially in cases where the remains are found in advanced decomposition, rendering traditional toxicological samples unavailable or unreliable. Entomotoxicology, an emerging methodology within forensic science, leverages insect specimens collected from cadavers as alternative toxicological samples. Several laboratory and field research studies have highlighted the efficacy in detecting various drugs, toxins, and elements absorbed by insects feeding on cadaveric tissues, even at low concentrations. However, correlation studies between drug concentrations in conventional matrices and insects remain controversial due to unknown factors influencing drug metabolism and larval feeding activity. This paper presents four real cases in which human cadavers were discovered in advanced stages of decomposition, and toxicological analyses were performed on both insect samples and available matrices. The results presented complement the scant literature currently available on the application of entomotoxicology in real cases, providing insights into the correlation between larvae and human specimen results. Furthermore, guidelines to collect and preserve entomological evidence at the crime scene and during the autopsy for use in entomotoxicological analyses are provided. This advancement holds promise in aiding forensic investigations, particularly in cases where traditional methods cannot be applied or require supporting data for further validation.
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Affiliation(s)
- Michela Peruch
- Department of Medical Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (M.P.); (M.B.)
| | - Maria Buffon
- Department of Medical Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (M.P.); (M.B.)
| | - Zlatko Jakovski
- Medical Faculty, Institute for Forensic Medicine, Criminology and Medical deontology, University of St. Cyril and Methodius, 1000 Skopje, North Macedonia;
| | - Chara Spiliopoulou
- Department of Forensic Medicine and Toxicology, School of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias, 115 27 Athens, Greece;
| | - Riccardo Addobbati
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34137 Trieste, Italy; (R.A.); (M.F.)
| | - Martina Franzin
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34137 Trieste, Italy; (R.A.); (M.F.)
| | - Paola A. Magni
- School of Medical, Molecular & Forensic Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Stefano D’Errico
- Department of Medical Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (M.P.); (M.B.)
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Badu IK, Asante D, Agyemang ED, Kwaku Duah K, Adokoh CK, Girela-Lopez E. Diatoms in maggots; a potential tool for drowning diagnosis - A preliminary study. MEDICINE, SCIENCE, AND THE LAW 2024:258024241241374. [PMID: 38557251 DOI: 10.1177/00258024241241374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Advanced putrefaction causes extensive loss of soft tissue, rendering it difficult to use the diatom test as a reliable diagnostic tool for drowning investigations. A positive diatom test in carrion insect larvae may provide significant assistance in overcoming the challenge of decomposition. The studies determined the utility of diatom test in carrion larvae on severely decomposed bodies. A modified acid digestion method involving nitric acid, K2Cr2O7 and HCl, was used to digest the blowfly larvae feeding on piglet carrion previously drowned in freshwater and sea water, respectively. Extracted diatom frustules were analysed and characterised using light microscopy coupled to a digital camera. Diatoms recovered from maggots on sea-drowned piglets were similar to diatoms from sea water (drowning medium). Centric diatoms recovered in maggots were higher (200 ± 60 diatoms/ mL) than pennate diatoms (80 ± 20 diatoms/mL). Isolated diatoms common to both maggots and water samples included Coscinodiscus sp. and Navicular spp. Albeit, there were no diatoms recovered from maggots on freshwater-drowned piglets. The findings of this study suggest that the diatom test is still a reliable diagnostic tool to determine if drowning was involved in the death of a fully decomposed body. This is the first study that isolated diatoms from maggots feeding on drowned bodies. It serves as the basis for further research into the utility of maggots for drowning investigations.
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Affiliation(s)
- I K Badu
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - D Asante
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - E D Agyemang
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - K Kwaku Duah
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - C K Adokoh
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - E Girela-Lopez
- Section of Legal and Forensic Medicine, Faculty of Medicine and Nursing, University of Córdoba, Córdoba, Spain
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Abdullah SR, Shafie MS, Wahid SA. Forensically important fly larvae on floating corpses in Malaysia: three case reports. EGYPTIAN JOURNAL OF FORENSIC SCIENCES 2022. [DOI: 10.1186/s41935-022-00275-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Understanding how environmental conditions can influence the insect distribution on corpses is essential to determine the postmortem interval. However, literatures related to forensically important flies in an aquatic environment were scarce. We report herewith a case series comprising three forensic cases related to floating corpses infested with fly larvae in Kuala Lumpur, Malaysia.
Case presentation
Case 1 involved the corpse of a 43-year old male found in the waterside of an abandoned mine. Case 2 was a 40-year-old male floating on a river stream, while case 3 was an 11-year-old boy who was found trapped in a monsoon drain after heavy rain. Numerous larvae of various stages, identified as Chrysomya megacephala (Calliphoridae) species, were collected in all cases even though the number of larvae was relatively lower compared to those usually collected on corpses found on terrestrial areas. Besides, the larvae of Eristalis spp. (Syrphidae), which are known to be exclusively associated with water bodies, were found in two of the cases. The blowfly Ch. rufifacies (Calliphoridae) larvae were collected only in case 3.
Conclusions
These findings show that both Ch. megacephala and Ch. rufifacies can be found in the ecologically varied death scene habitats including aquatic areas. Meanwhile, the presence of Eristalis spp. can be used as an indicator of death location associated with an aquatic environment. The challenges and limitations of analyzing entomological evidence on bodies discovered in aquatic environments were also discussed.
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Pinto J, Magni PA, O’Brien RC, Dadour IR. Domestic Filth Flies in New Haven, Connecticut: A Case Study on the Effects of Urbanization and Climate Change by Comparing Fly Populations after 78 Years. INSECTS 2021; 12:insects12110972. [PMID: 34821773 PMCID: PMC8623608 DOI: 10.3390/insects12110972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/04/2022]
Abstract
Simple Summary Domestic filth fly population data were collected in the summers of 1942–1944 in the urban city of New Haven, Connecticut, during a polio epidemic. The current survey was completed 78 years later by setting out a weekly trap in the same region during June–September over a two-year period. Results indicate that the fly population has changed in the city, with 16 fewer species trapped overall, and there have been changes in the fly species trapped. Some species have increased in abundance, notably Lucilia coeruleiviridis, while numbers of the common Lucilia sericata have decreased, and Lucilia illustris was absent. Changes in land cover and climate were also assessed to show that the trap site has experienced significant habitat change, together with an increase in the average temperature and rainfall. Fly numbers were significantly affected by temperature and rainfall in both the 1940s and the current survey. The results of this study suggest the prolonged period of urbanization of the region is influencing the domestic filth fly population. Abstract Changes in common and widespread insect populations such as the domestic filth fly in urban cities are useful and relevant bioindicators for overall changes in the insect biomass. The current study surveyed necrophagous flies by placing a weekly trap from June–September over a two-year period in the city of New Haven, Connecticut, to compare data on fly abundance and diversity with data collected 78 years earlier. Climate and land cover changes were also assessed in combination with the fly population for each period. The survey results suggest the domestic filth fly population is now less diverse with decreased species richness and changes in the relative abundance of species. In both surveys, 95–96% of the population was composed of only three species. The current survey data indicate the numerical dominance of Lucilia sericata has decreased, the abundance of several species, notably Lucilia coeruleiviridis, has increased, and Lucilia illustris is absent. Species that showed a significant interaction with temperature in the 1940s survey have now increased in abundance, with several of the trapped species continuing to show an interaction with temperature and rainfall. Analysis of the land cover and climate data characterizes the trap site as a region exposed to a prolonged period of industrialization and urbanization, with only 7% of the land cover remaining undeveloped and over 50% impervious, coupled with an increase in temperature and rainfall. This study serves as a model for changes in domestic filth fly populations and other insects in similarly highly urbanized established cities.
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Affiliation(s)
- Julie Pinto
- Discipline of Medical, Molecular & Forensic Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia;
- Correspondence:
| | - Paola A. Magni
- Discipline of Medical, Molecular & Forensic Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia;
- Murdoch University Singapore, King’s Centre, 390 Havelock Road, Singapore 169662, Singapore
| | - R. Christopher O’Brien
- Criminal Justice and Forensic Sciences Department, Henry C. Lee College of Criminal Justice and Forensic Sciences, University of New Haven, West Haven, CT 06516, USA;
| | - Ian R. Dadour
- Source Certain International Pty Ltd., P.O. Box 1570, Wangara DC, WA 6947, Australia;
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